The purpose of this project is to study the action of fluoride in various systems used to detect clastogenic or mutagenic substances. To date fluoride has been examined in several systems used to detect mutagens and found to be non mutagenic. No effects on chromosome structure were noted in animals given widely different levels of fluoride. DNA repair after X-ray was unchanged by fluoride. No genetic effects of fluoride were noted in a recessive lethal test of fluoride on drosophila. The data indicate that fluoride has no mutagenic activity. Ongoing studies and reports of fluoride effects on metabolism and growth in the literature are being monitored.